WSUS: Console fails to connect with "The WSUS administration console was unable to connect to the WSUS Server via the remote API" error

Here's an interesting one that was recently written up by David Kirchmer, one of our Senior Support Engineers from Charlotte, North Carolina.  If you're getting errors such as "The WSUS administration console was unable to connect to the WSUS Server via the remote API" when you try to connect with the WSUS MMC then you might do some testing with your firewall software to see if that's a factor:

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Issue: The WSUS Admin Console (MMC snap-in) opens but when trying to connect to the WSUS server instance on the same machine the following error may be displayed:

The WSUS administration console was unable to connect to the WSUS Server via the remote API.

You may also see errors such as:

The WSUS administration console has encountered an unexpected error. This may be a transient error; try restarting the administration console.

or

System.IO.IOException -- The handshake failed due to an unexpected packet format.

Cause: This can be caused if you have a firewall installed on the local system that is blocking the connection attempts made by the WSUS console.

Resolution: Either disable the firewall or configure a rule to allow the connection.

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We've seen a couple calls on this and there's even a forum post that talks about this as well.  If you're getting the errors mentioned above try temporarily disabling the firewall just to see if it starts working.  If it does then you know that's the root of your problem.  Once you've identified the firewall as the cause of the problem you can then investigate the changes or rules necessary to allow WSUS to successfully connect.

Thanks David!

J.C. Hornbeck | Manageability Knowledge Engineer